This story has been updated with the information that the center has been approved to begin patient care on Oct. 5.

NORTHAMPTON - The new Mass General Cancer Center at Cooley Dickinson Hospital is officially open this week with a ribbon cutting ceremony Sept. 16 and tours for donors and legislators.

Hospital officials received notification the same day that the Massachusetts Department of Health had completed its review and approved the center. Care of patients in the physical space will begin Oct. 5.

The center is an expansion of a collaboration begun in 2009. It will be operated by Mass General Hospital Cancer Center, with Cooley Dickinson's cancer care doctors becoming Mass General Hospital physicians.

Cooley Dickinson became an affiliate of that hospital in 2013. It remains an independently licensed hospital with its own medical staff and board of trustees.

The Boston-based hospital has a licensed Mass General Cancer Care Center at Emerson Hospital - Bethke in Concord, as well as one in Waltham and Danvers.

"This is about getting Mass General Cancer Center quality at Cooley Dickinson Hospital," said Dr. Sean Mullally, a medical oncologist and medical director of the Mass General Cancer Center at Cooley Dickinson Hospital

He added in a release that patients "can come here and their team will help them decide what care they should receive and where."

The new center is said to expand treatment options for patients as well as genetic counseling, give greater access to clinical trials and provide coordinated care across disciplines

The 16,400 square foot center, under construction in the North Building since the winter at a cost of $5 million, centralizes cancer care at the hospital. Services within the facility, built above the radiation department, will include offices and exam rooms, infusion areas for chemotherapy, as well as an on-site pharmacy.

The center consists of 3,400 square feet of new space, and 13,000 square feet of renovated existing space. It is said to quadruple the footprint for oncology care.

Features include 10 exam rooms; an 18-chair infusion bay with chairs that allow patients to receive treatment for up to eight hours, and a video conferencing room for tele-consultations.